research team member; co-investigator
Refers to a person who shares responsibility in a research project, typically in academic or institutional settings.
He joined the project as a research team member.
研究代表者 is the principal investigator or lead researcher, while 研究分担者 is a co-investigator or member who shares research duties.
Compound of 研究 (research), 分担 (sharing of duties), and 者 (person).